U.S. Pat. No. 3,530,220, issued Sept. 22, 1970, to James B. Buchanan, discloses a class of 1-carbamoyl-N-(substituted carbamoyloxy)thioformimidates of the general formula ##STR5## where the R's represent hydrogen or certain organic radicals and R' and R" represent certain organic radicals. The compounds are insecticides, acaricides, and nematocides. The patent discloses preparation of the compounds from intermediate 1-carbamoyl-N-hydroxythioformimidates of the general formula ##STR6## The present invention resulted from efforts to discover new biologically active compounds which could be prepared from these intermediates.